The present invention generally relates to a continuous heat-treating furnace and, more particularly to a continuous annealing furnace having a feature of minimizing energy consumption.
A continuous heat-treatment furnace comprising a single unitary housing structure having preheating, high temperature and cooling zones defined therein has long been well known. In this known heat-treatment furnace, various attempts have been made to minimize the energy consumption.
According to, for example, the Japanese Patent Publication No. 45-10610, published in 1970, in order to save the energy the furnace consumes, there is disclosed a continuous heat-treatment furnace having its interior partitioned by a partition wall so as to define therein the path of conveyance of materials to be continuously heat-treated generally in the shape of a figure "U" with the preheating and cooling zones situated on respective sides of the partition wall and extending generally in a parallel relationship to each other. For effecting the heat exchange between the preheating and cooling zones, the top of the partition wall inside the unitary housing structure is spaced a distance from the ceiling wall which overlays both of the preheating and cooling zones.
In this prior art construction, it has been found that, since the atmosphere inside either one of the preheating and cooling zones tends to mix with that inside the other at the same local area within the furnace, heat exchange between these zones does not take place efficiently and effectively and, therefore, a desired or required temperature difference cannot be obtained between the temperature of the materials being treated and that at such local area.